A printing device authenticates the user by using an operating panel and an IC (Integrated Circuit) card, and restricts functions including a function of deleting data. To be authenticated, the user with the IC card inputs a password and E-mail address by using the operating panel. One such device is disclosed in a document on the web (URL: http://www.sharp.co.jp/products/mx4501fn/text/security.html), Sharp Corporation. The published date of this document is unknown. However, the inventors of this application were familiar with this document at the time of Mar. 23, 2006.
In addition, an image forming device, disclosed in U.S. Patent Application Publication No. 2005/213997 A1 (corresponding to Japanese Patent Application Publication No. 2005-301212) communicates with an IC tag mounted in a consumable part, and determines whether the consumable part mounting the IC tag can be used based on information obtained from the IC tag by the communication. If the consumable part cannot be used, the image forming device restricts the user from accessing information stored in a storage area of the IC tag mounted in the consumable part.